1. Technical Field
The present invention relates to navigation and, in particular, to navigation in a building or store. More particularly, the present invention relates to a method, apparatus, and program for calibration of a navigation device while navigating an environment.
2. Description of Related Art
Finding items in a store is often difficult, particularly for people with disabilities, such as vision impairment. Often, a shopper must ask store personnel the locations of items, which typically results in only an aisle number.
One prior art solution is to provide a directory or kiosk to direct shoppers to items within the store. However, shoppers often must make several trips back to the directory or kiosk to locate multiple items, resulting in inefficient use of time and unnecessary travel within the store.
Another prior art solution is to provide shoppers with a device on a shopping cart. The devices communicate with beacons within the store to determine a general location. However, to accurately determine the location, many beacons must be wired throughout the entire store, which is costly and cumbersome. Furthermore, the devices provide only a general location and vicinity to items. The devices do not determine an orientation or direction of the shopper. Thus, the devices cannot effectively direct the shopper to items within the store. The devices must also be in continuous contact with beacons. Thus, the devices are reliant upon the operability and accuracy of the system of beacons in the store.
Prior art navigation devices use global positioning systems (GPS) to determine position within a geographical region. However, GPS is not accurate enough for navigating a small area such as a store and differentiating among locations that may be adjacent to each other or above or below each other in a three dimensional space.
Prior art store systems are typically employed with the assumption that users will use sight to locate items, thus accuracy is not an issue. However, visually impaired people may require specific feedback regarding location and orientation within the environment. For example, a direction of xe2x80x9chalfway up the aislexe2x80x9d is not useful unless the person can visually estimate a location within the aisle.
Therefore, it would be advantageous to have an improved method and apparatus for navigation within a store.
The present invention provides a device for navigation within a building or store. The device includes accelerometers for measuring the movement of the device. Given a beginning location and orientation, the device determines a current location, orientation, and speed based on the information from the accelerometers. A user enters a designated location within a building or store such as a restroom, customer service, sales counter, etc., or a list of items such as a shopping list, into the device; and the device determines a path to the location or items. The device then generates and presents directions for navigation. The path may be calculated to avoid hazards, such as shelves being stocked, congested checkout lines, and spilled items. Thus, a visually impaired person may use the device to safely navigate the store and locate items. The directions may be generated as speech to the user through a speaker, headphones, or an earpiece.
Planes of infrared beams are arranged within the environment such that a navigation device is likely to or must pass through a plane. A path may be computed to ensure that the navigation device passes through an IR plane. The navigation device has a plurality of IR sensors arranged in a tetrahedron. As the device passes through an IR plane, the device receives signals from the sensors. Given the order and timing of the signals and a location of the IR plane, the device performs a calibration in all three directions. The device is calibrated without requiring the user to place the device in a cradle.